<?php
//将数据格式化成树形结构（无极限分类）
//数组中的健值要和id相同
$arr = array(
    1 => array('id' => 1, 'pid' => 0, 'name' => '江西省'),
    2 => array('id' => 2, 'pid' => 0, 'name' => '黑龙江省'),
    3 => array('id' => 3, 'pid' => 1, 'name' => '南昌市'),
    4 => array('id' => 4, 'pid' => 2, 'name' => '哈尔滨市'),
    5 => array('id' => 5, 'pid' => 2, 'name' => '鸡西市'),
    6 => array('id' => 6, 'pid' => 4, 'name' => '香坊区'),
    7 => array('id' => 7, 'pid' => 4, 'name' => '南岗区'),
    8 => array('id' => 8, 'pid' => 6, 'name' => '和兴路'),
    9 => array('id' => 9, 'pid' => 7, 'name' => '西大直街'),
    10 => array('id' => 10, 'pid' => 8, 'name' => '东北林业大学'),
    11 => array('id' => 11, 'pid' => 9, 'name' => '哈尔滨工业大学'),
    12 => array('id' => 12, 'pid' => 8, 'name' => '哈尔滨师范大学'),
    13 => array('id' => 13, 'pid' => 1, 'name' => '赣州市'),
    14 => array('id' => 14, 'pid' => 13, 'name' => '赣县'),
    15 => array('id' => 15, 'pid' => 13, 'name' => '于都县'),
    16 => array('id' => 16, 'pid' => 14, 'name' => '茅店镇'),
    17 => array('id' => 17, 'pid' => 14, 'name' => '大田乡'),
    18 => array('id' => 18, 'pid' => 16, 'name' => '义源村'),
    19 => array('id' => 19, 'pid' => 16, 'name' => '上坝村'),
);

function getTeee5($arr) { 
    foreach ($arr as $v) 
        $arr[$v['pid']]['son'][$v['id']] = &$arr[$v['id']]; 
    return isset($arr[0]['son']) ? $arr[0]['son'] : array(); 
} 

function getTeee9($arr) {
    $tree = array(); //格式化好的树
    foreach ($arr as $v)
        if (isset($arr[$v['pid']]))
            $arr[$v['pid']]['son'][] = &$arr[$v['id']];
        else
            $tree[] = &$arr[$v['id']];
    return $tree;
}

//上面两个方法是网络里面找的，下面这个方法是自己写的
function get_tree($arr){
	foreach($arr as $v){
		$arr[$v['pid']]['son'][] = &$arr[$v['id']];
	}
	return $arr[0]['son'];
}

echo "<pre>";
//print_r(getTeee5($arr));
//print_r(getTeee9($arr));
print_r(get_tree($arr));
echo "</pre>";
